The invention relates to a single sheet feed device for an electrophotographic printer or copier which spans the single sheet feed device. In such printers or copiers, exacting requirements are made of the printing speed. In printers or copiers according to the prior art a printing speed of approximately 50 sheets per minute (for example in the DIN A4 format) is achieved. The single sheets are drawn from a single sheet stack and successively fed by a removal device to a recording carrier conveying path of the single sheet feed device. A printing unit which contains a developer station and a fixing station is arranged in the course of the recording carrier conveying path. A print image is transferred to a single sheet in the developer station and in the fixing station this print image is fixed on the single sheet. In order to ensure sufficient quality of the print image, the development and fixing process can only be accelerated up to a maximum processing speed. A further increase in the processing speed with constant printing quality is consequently not possible by merely increasing the transfer and fixing speed and thus the conveying speed of the single sheets.
U.S. Pat. No. 4,587,532 discloses a sheet feed device and a sheet delivery device which are suitable for feeding single sheets to a plurality of printers operating in synchronism. The single sheets are present in the form of a stack of single sheets. The sheet feed device and the sheet delivery device ensure that a single sheet is fed to each printer at the correct time before the subsequent printing cycle begins and a printed single sheet is conveyed away from said printer. The length of the path and the speed of the sheets are selected appropriately. The feeding speed is higher than the processing speed. However, in order to increase the printing speed a plurality of printing units arranged one on top of the other is required.
U.S. Pat. No. 4,431,322 discloses a printing device with two recording carrier conveying paths which can be selected by means of a switch. Pairs of drive rollers are arranged along the recording carrier conveying paths. These pairs of drive rollers are driven by means of belts. Belt speed-transforming transmission means are provided which can be used to realize different speeds of the pairs of drive rollers. In order to increase the printing speed, two printing units are arranged one on top of the other. Each of the two printing units is assigned a recording carrier conveying path.
U.S. Pat. No. 4,727,402 discloses a single sheet feed device for ordering single sheet information carriers in which single sheets can be drawn off sideways from a stack of single sheets and can be fed to a conveying path in such a way that two single sheets can be conveyed lying one next to the other. The single sheet feed device has a plurality of mechanical and movable individual components, for which reason complex adjustment and frequent maintenance of the single sheet feed device are to be expected.